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The interaction and infiltration behavior between typical calcium–ferrum–alumina–silicate (CFAS) and Yb4Hf3O12 ceramics at 1300, 1400, and 1500°C for different duration times were investigated. At 1300°C, the CFAS melt first crystallized and then generated massive anorthite with high‐melting point, reducing the wettability of CFAS melt and physically blocking CFAS penetration paths. As the temperature increased to 1400°C and 1500°C, the wettability of the molten CFAS correspondingly increases. A continuous reaction layer, composed of apatite, fluorite, and garnet, was formed over Yb4Hf3O12 ceramic due to the penetration of CFAS melt. Furthermore, the infiltration rate of CFAS decreases with increasing corrosion time because of the barrier effect primarily derived from the as‐mentioned continuous reaction layer. [ABSTRACT FROM AUTHOR]

High-temperature molten silicate deposit corrosion has become a critical factor for the failure of thermal barrier coatings. In this work, promising ytterbium hafnate ceramics with different HfO 2 content were prepared by solid-phase reaction, and the effect of HfO 2 content on Fe-containing silicate corrosion behavior of ytterbium hafnate ceramics was investigated. The evolution of HfO 2 content showed negligible influences on reaction products and corrosion mechanism. The attack of Fe-containing silicate melts on the ceramic led to the formation of a reaction layer consisting of apatite, fluorite, and garnet. This layer plays a critical role in preventing further penetration of the melts. However, ytterbium hafnate ceramics with lower HfO 2 content showed better resistance to melt attack. [ABSTRACT FROM AUTHOR]